/*
 * BLEDevice.cpp
 *
 *  Created on: Mar 22, 2017
 *      Author: kolban
 */
#include "soc/soc_caps.h"
#if SOC_BLE_SUPPORTED

#include "sdkconfig.h"
#if defined(CONFIG_BLUEDROID_ENABLED)
#include <esp_bt.h>
#include <esp_bt_main.h>
#include <esp_gap_ble_api.h>
#include <esp_gattc_api.h>
#include <esp_gatt_common_api.h>// ESP32 BLE
#include "BLEClient.h"
#include "BLEUtils.h"
#include "BLEService.h"
#include "GeneralUtils.h"
#include <string>
#include <sstream>
#include <unordered_set>
#include "BLEDevice.h"
#include "esp32-hal-log.h"

/*
 * Design
 * ------
 * When we perform a searchService() requests, we are asking the BLE server to return each of the services
 * that it exposes.  For each service, we received an ESP_GATTC_SEARCH_RES_EVT event which contains details
 * of the exposed service including its UUID.
 *
 * The objects we will invent for a BLEClient will be as follows:
 * * BLERemoteService - A model of a remote service.
 * * BLERemoteCharacteristic - A model of a remote characteristic
 * * BLERemoteDescriptor - A model of a remote descriptor.
 *
 * Since there is a hierarchical relationship here, we will have the idea that from a BLERemoteService will own
 * zero or more remote characteristics and a BLERemoteCharacteristic will own zero or more remote BLEDescriptors.
 *
 * We will assume that a BLERemoteService contains a map that maps BLEUUIDs to the set of owned characteristics
 * and that a BLECharacteristic contains a map that maps BLEUUIDs to the set of owned descriptors.
 *
 *
 */

BLEClient::BLEClient() {
  m_pClientCallbacks = nullptr;
  m_conn_id          = ESP_GATT_IF_NONE;
  m_gattc_if         = ESP_GATT_IF_NONE;
  m_haveServices     = false;
  m_isConnected      = false;  // Initially, we are flagged as not connected.
} // BLEClient


/**
 * @brief Destructor.
 */
BLEClient::~BLEClient() {
  // We may have allocated service references associated with this client.  Before we are finished
  // with the client, we must release resources.
  for (auto &myPair : m_servicesMap) {
     delete myPair.second;
  }
  m_servicesMap.clear();
  m_servicesMapByInstID.clear();
} // ~BLEClient


/**
 * @brief Clear any existing services.
 *
 */
void BLEClient::clearServices() {
  log_v(">> clearServices");
  // Delete all the services.
  for (auto &myPair : m_servicesMap) {
     delete myPair.second;
  }
  m_servicesMap.clear();
  m_haveServices = false;
  log_v("<< clearServices");
} // clearServices

/**
 * Add overloaded function to ease connect to peer device with not public address
 */
bool BLEClient::connect(BLEAdvertisedDevice* device) {
  BLEAddress address =  device->getAddress();
  esp_ble_addr_type_t type = device->getAddressType();
  return connect(address, type);
}

/**
 * @brief Connect to the partner (BLE Server).
 * @param [in] address The address of the partner.
 * @return True on success.
 */
bool BLEClient::connect(BLEAddress address, esp_ble_addr_type_t type) {
  log_v(">> connect(%s)", address.toString().c_str());

// We need the connection handle that we get from registering the application.  We register the app
// and then block on its completion.  When the event has arrived, we will have the handle.
  m_appId = BLEDevice::m_appId++;
  BLEDevice::addPeerDevice(this, true, m_appId);
  m_semaphoreRegEvt.take("connect");

  // clearServices(); // we dont need to delete services since every client is unique?
  esp_err_t errRc = ::esp_ble_gattc_app_register(m_appId);
  if (errRc != ESP_OK) {
    log_e("esp_ble_gattc_app_register: rc=%d %s", errRc, GeneralUtils::errorToString(errRc));
    BLEDevice::removePeerDevice(m_appId, true);
    return false;
  }

  uint32_t rc = m_semaphoreRegEvt.wait("connect");

  if (rc != ESP_GATT_OK) {
    // fixes ESP_GATT_NO_RESOURCES error mostly
    log_e("esp_ble_gattc_app_register_error: rc=%d", rc);
    BLEDevice::removePeerDevice(m_appId, true);
    // not sure if this is needed here
    // esp_ble_gattc_app_unregister(m_gattc_if);
    // m_gattc_if = ESP_GATT_IF_NONE;
    return false;
  }

  m_peerAddress = address;

  // Perform the open connection request against the target BLE Server.
  m_semaphoreOpenEvt.take("connect");
  errRc = ::esp_ble_gattc_open(
    m_gattc_if,
    *getPeerAddress().getNative(), // address
    type,          // Note: This was added on 2018-04-03 when the latest ESP-IDF was detected to have changed the signature.
    1                              // direct connection <-- maybe needs to be changed in case of direct indirect connection???
  );
  if (errRc != ESP_OK) {
    log_e("esp_ble_gattc_open: rc=%d %s", errRc, GeneralUtils::errorToString(errRc));
    BLEDevice::removePeerDevice(m_appId, true);
    return false;
  }

  rc = m_semaphoreOpenEvt.wait("connect");   // Wait for the connection to complete.
  // check the status of the connection and cleanup in case of failure
  if (rc != ESP_GATT_OK) {
    BLEDevice::removePeerDevice(m_appId, true);
    esp_ble_gattc_app_unregister(m_gattc_if);
    m_gattc_if = ESP_GATT_IF_NONE;
  }
  log_v("<< connect(), rc=%d", rc==ESP_GATT_OK);
  return rc == ESP_GATT_OK;
} // connect


/**
 * @brief Disconnect from the peer.
 * @return N/A.
 */
void BLEClient::disconnect() {
  log_v(">> disconnect()");
  esp_err_t errRc = ::esp_ble_gattc_close(getGattcIf(), getConnId());
  if (errRc != ESP_OK) {
    log_e("esp_ble_gattc_close: rc=%d %s", errRc, GeneralUtils::errorToString(errRc));
    return;
  }
  log_v("<< disconnect()");
} // disconnect


/**
 * @brief Handle GATT Client events
 */
void BLEClient::gattClientEventHandler(
  esp_gattc_cb_event_t      event,
  esp_gatt_if_t             gattc_if,
  esp_ble_gattc_cb_param_t* evtParam) {

  log_d("gattClientEventHandler [esp_gatt_if: %d] ... %s",
    gattc_if, BLEUtils::gattClientEventTypeToString(event).c_str());

  // it is possible to receive events from other connections while waiting for registration
  if (m_gattc_if == ESP_GATT_IF_NONE && event != ESP_GATTC_REG_EVT) {
    return;
  }

  // Execute handler code based on the type of event received.
  switch(event) {

    case ESP_GATTC_SRVC_CHG_EVT:
      log_i("SERVICE CHANGED");
      break;

    case ESP_GATTC_CLOSE_EVT: {
        // esp_ble_gattc_app_unregister(m_appId);
        // BLEDevice::removePeerDevice(m_gattc_if, true);
      break;
    }

    //
    // ESP_GATTC_DISCONNECT_EVT
    //
    // disconnect:
    // - esp_gatt_status_t status
    // - uint16_t          conn_id
    // - esp_bd_addr_t     remote_bda
    case ESP_GATTC_DISCONNECT_EVT: {
        if (evtParam->disconnect.conn_id != getConnId()) break;
        // If we receive a disconnect event, set the class flag that indicates that we are
        // no longer connected.
        bool m_wasConnected = m_isConnected;
        m_isConnected = false;
        esp_ble_gattc_app_unregister(m_gattc_if);
        m_gattc_if = ESP_GATT_IF_NONE;
        m_semaphoreOpenEvt.give(ESP_GATT_IF_NONE);
        m_semaphoreRssiCmplEvt.give();
        m_semaphoreSearchCmplEvt.give(1);
        BLEDevice::removePeerDevice(m_appId, true);
        if (m_wasConnected && m_pClientCallbacks != nullptr) {
          m_pClientCallbacks->onDisconnect(this);
        }
        break;
    } // ESP_GATTC_DISCONNECT_EVT

    //
    // ESP_GATTC_OPEN_EVT
    //
    // open:
    // - esp_gatt_status_t status
    // - uint16_t          conn_id
    // - esp_bd_addr_t     remote_bda
    //
    case ESP_GATTC_OPEN_EVT: {
      m_conn_id = evtParam->open.conn_id;
      if (evtParam->open.status == ESP_GATT_OK) {
        m_isConnected = true;   // Flag us as connected.
        if (m_pClientCallbacks != nullptr) {
          m_pClientCallbacks->onConnect(this);
        }
      } else {
        log_e("Failed to connect, status=%s", GeneralUtils::errorToString(evtParam->open.status));
      }
      m_semaphoreOpenEvt.give(evtParam->open.status);
      break;
    } // ESP_GATTC_OPEN_EVT


    //
    // ESP_GATTC_REG_EVT
    //
    // reg:
    // esp_gatt_status_t status
    // uint16_t          app_id
    //
    case ESP_GATTC_REG_EVT: {
      m_gattc_if = gattc_if;
      // pass on the registration status result, in case of failure
      m_semaphoreRegEvt.give(evtParam->reg.status);
      break;
    } // ESP_GATTC_REG_EVT

    case ESP_GATTC_CFG_MTU_EVT:
      if (evtParam->cfg_mtu.conn_id != getConnId()) break;
      if(evtParam->cfg_mtu.status != ESP_GATT_OK) {
        log_e("Config mtu failed");
      }
      m_mtu = evtParam->cfg_mtu.mtu;
      break;

    case ESP_GATTC_CONNECT_EVT: {
      if (evtParam->connect.conn_id != getConnId()) break;
      BLEDevice::updatePeerDevice(this, true, m_appId);
      esp_err_t errRc = esp_ble_gattc_send_mtu_req(gattc_if, evtParam->connect.conn_id);
      if (errRc != ESP_OK) {
        log_e("esp_ble_gattc_send_mtu_req: rc=%d %s", errRc, GeneralUtils::errorToString(errRc));
      }
#ifdef CONFIG_BLE_SMP_ENABLE   // Check that BLE SMP (security) is configured in make menuconfig
      if(BLEDevice::m_securityLevel){
        esp_ble_set_encryption(evtParam->connect.remote_bda, BLEDevice::m_securityLevel);
      }
#endif  // CONFIG_BLE_SMP_ENABLE
      break;
    } // ESP_GATTC_CONNECT_EVT

    //
    // ESP_GATTC_SEARCH_CMPL_EVT
    //
    // search_cmpl:
    // - esp_gatt_status_t status
    // - uint16_t          conn_id
    //
    case ESP_GATTC_SEARCH_CMPL_EVT: {
      if (evtParam->search_cmpl.conn_id != getConnId()) break;
      esp_ble_gattc_cb_param_t* p_data = (esp_ble_gattc_cb_param_t*)evtParam;
      if (p_data->search_cmpl.status != ESP_GATT_OK){
        log_e("search service failed, error status = %x", p_data->search_cmpl.status);
        break;
      }
#ifndef ARDUINO_ARCH_ESP32
// commented out just for now to keep backward compatibility
      // if(p_data->search_cmpl.searched_service_source == ESP_GATT_SERVICE_FROM_REMOTE_DEVICE) {
      //   log_i("Get service information from remote device");
      // } else if (p_data->search_cmpl.searched_service_source == ESP_GATT_SERVICE_FROM_NVS_FLASH) {
      //   log_i("Get service information from flash");
      // } else {
      //   log_i("unknown service source");
      // }
#endif
      m_semaphoreSearchCmplEvt.give(0);
      break;
    } // ESP_GATTC_SEARCH_CMPL_EVT


    //
    // ESP_GATTC_SEARCH_RES_EVT
    //
    // search_res:
    // - uint16_t      conn_id
    // - uint16_t      start_handle
    // - uint16_t      end_handle
    // - esp_gatt_id_t srvc_id
    //
    case ESP_GATTC_SEARCH_RES_EVT: {
      if (evtParam->search_res.conn_id != getConnId()) break;
      BLEUUID uuid = BLEUUID(evtParam->search_res.srvc_id);
      BLERemoteService* pRemoteService = new BLERemoteService(
        evtParam->search_res.srvc_id,
        this,
        evtParam->search_res.start_handle,
        evtParam->search_res.end_handle
      );
      m_servicesMap.insert(std::pair<String, BLERemoteService*>(uuid.toString(), pRemoteService));
      m_servicesMapByInstID.insert(std::pair<BLERemoteService *, uint16_t>(pRemoteService, evtParam->search_res.srvc_id.inst_id));
      break;
    } // ESP_GATTC_SEARCH_RES_EVT


    default: {
      break;
    }
  } // Switch

  // Pass the request on to all services.
  for (auto &myPair : m_servicesMap) {
     myPair.second->gattClientEventHandler(event, gattc_if, evtParam);
  }

} // gattClientEventHandler


uint16_t BLEClient::getConnId() {
  return m_conn_id;
} // getConnId



esp_gatt_if_t BLEClient::getGattcIf() {
  return m_gattc_if;
} // getGattcIf


/**
 * @brief Retrieve the address of the peer.
 *
 * Returns the Bluetooth device address of the %BLE peer to which this client is connected.
 */
BLEAddress BLEClient::getPeerAddress() {
  return m_peerAddress;
} // getAddress


/**
 * @brief Ask the BLE server for the RSSI value.
 * @return The RSSI value.
 */
int BLEClient::getRssi() {
  log_v(">> getRssi()");
  if (!isConnected()) {
    log_v("<< getRssi(): Not connected");
    return 0;
  }
  // We make the API call to read the RSSI value which is an asynchronous operation.  We expect to receive
  // an ESP_GAP_BLE_READ_RSSI_COMPLETE_EVT to indicate completion.
  //
  m_semaphoreRssiCmplEvt.take("getRssi");
  esp_err_t rc = ::esp_ble_gap_read_rssi(*getPeerAddress().getNative());
  if (rc != ESP_OK) {
    log_e("<< getRssi: esp_ble_gap_read_rssi: rc=%d %s", rc, GeneralUtils::errorToString(rc));
    return 0;
  }
  int rssiValue = m_semaphoreRssiCmplEvt.wait("getRssi");
  log_v("<< getRssi(): %d", rssiValue);
  return rssiValue;
} // getRssi


/**
 * @brief Get the service BLE Remote Service instance corresponding to the uuid.
 * @param [in] uuid The UUID of the service being sought.
 * @return A reference to the Service or nullptr if don't know about it.
 */
BLERemoteService* BLEClient::getService(const char* uuid) {
    return getService(BLEUUID(uuid));
} // getService


/**
 * @brief Get the service object corresponding to the uuid.
 * @param [in] uuid The UUID of the service being sought.
 * @return A reference to the Service or nullptr if don't know about it.
 * @throws BLEUuidNotFound
 */
BLERemoteService* BLEClient::getService(BLEUUID uuid) {
  log_v(">> getService: uuid: %s", uuid.toString().c_str());
// Design
// ------
// We wish to retrieve the service given its UUID.  It is possible that we have not yet asked the
// device what services it has in which case we have nothing to match against.  If we have not
// asked the device about its services, then we do that now.  Once we get the results we can then
// examine the services map to see if it has the service we are looking for.
  if (!m_haveServices) {
    getServices();
  }
  String uuidStr = uuid.toString();
  for (auto &myPair : m_servicesMap) {
    if (myPair.first == uuidStr) {
      log_v("<< getService: found the service with uuid: %s", uuid.toString().c_str());
      return myPair.second;
    }
  } // End of each of the services.
  log_v("<< getService: not found");
  return nullptr;
} // getService


/**
 * @brief Ask the remote %BLE server for its services.
 * A %BLE Server exposes a set of services for its partners.  Here we ask the server for its set of
 * services and wait until we have received them all.
 * @return N/A
 */
std::map<String, BLERemoteService*>* BLEClient::getServices() {
/*
 * Design
 * ------
 * We invoke esp_ble_gattc_search_service.  This will request a list of the service exposed by the
 * peer BLE partner to be returned as events.  Each event will be an an instance of ESP_GATTC_SEARCH_RES_EVT
 * and will culminate with an ESP_GATTC_SEARCH_CMPL_EVT when all have been received.
 */
  log_v(">> getServices");
// TODO implement retrieving services from cache
  clearServices(); // Clear any services that may exist.

  esp_err_t errRc = esp_ble_gattc_search_service(
    getGattcIf(),
    getConnId(),
    NULL            // Filter UUID
  );

  m_semaphoreSearchCmplEvt.take("getServices");
  if (errRc != ESP_OK) {
    log_e("esp_ble_gattc_search_service: rc=%d %s", errRc, GeneralUtils::errorToString(errRc));
    return &m_servicesMap;
  }
  // If sucessfull, remember that we now have services.
  m_haveServices = (m_semaphoreSearchCmplEvt.wait("getServices") == 0);
  log_v("<< getServices");
  return &m_servicesMap;
} // getServices


/**
 * @brief Get the value of a specific characteristic associated with a specific service.
 * @param [in] serviceUUID The service that owns the characteristic.
 * @param [in] characteristicUUID The characteristic whose value we wish to read.
 * @throws BLEUuidNotFound
 */
String BLEClient::getValue(BLEUUID serviceUUID, BLEUUID characteristicUUID) {
  log_v(">> getValue: serviceUUID: %s, characteristicUUID: %s", serviceUUID.toString().c_str(), characteristicUUID.toString().c_str());
  String ret = getService(serviceUUID)->getCharacteristic(characteristicUUID)->readValue();
  log_v("<<getValue");
  return ret;
} // getValue


/**
 * @brief Handle a received GAP event.
 *
 * @param [in] event
 * @param [in] param
 */
void BLEClient::handleGAPEvent(
    esp_gap_ble_cb_event_t  event,
    esp_ble_gap_cb_param_t* param) {
  log_d("BLEClient ... handling GAP event!");
  switch (event) {
    //
    // ESP_GAP_BLE_READ_RSSI_COMPLETE_EVT
    //
    // read_rssi_cmpl
    // - esp_bt_status_t status
    // - int8_t rssi
    // - esp_bd_addr_t remote_addr
    //
    case ESP_GAP_BLE_READ_RSSI_COMPLETE_EVT: {
      m_semaphoreRssiCmplEvt.give((uint32_t) param->read_rssi_cmpl.rssi);
      break;
    } // ESP_GAP_BLE_READ_RSSI_COMPLETE_EVT

    default:
      break;
  }
} // handleGAPEvent


/**
 * @brief Are we connected to a partner?
 * @return True if we are connected and false if we are not connected.
 */
bool BLEClient::isConnected() {
  return m_isConnected;
} // isConnected




/**
 * @brief Set the callbacks that will be invoked.
 */
void BLEClient::setClientCallbacks(BLEClientCallbacks* pClientCallbacks) {
  m_pClientCallbacks = pClientCallbacks;
} // setClientCallbacks


/**
 * @brief Set the value of a specific characteristic associated with a specific service.
 * @param [in] serviceUUID The service that owns the characteristic.
 * @param [in] characteristicUUID The characteristic whose value we wish to write.
 * @throws BLEUuidNotFound
 */
void BLEClient::setValue(BLEUUID serviceUUID, BLEUUID characteristicUUID, String value) {
  log_v(">> setValue: serviceUUID: %s, characteristicUUID: %s", serviceUUID.toString().c_str(), characteristicUUID.toString().c_str());
  getService(serviceUUID)->getCharacteristic(characteristicUUID)->writeValue(value);
  log_v("<< setValue");
} // setValue

uint16_t BLEClient::getMTU() {
  return m_mtu;
}


/**
  @brief Set the local and remote MTU size.
         Should be called once after client connects if MTU size needs to be changed.
  @return bool indicating if MTU was successfully set locally and on remote.
*/
bool BLEClient::setMTU(uint16_t mtu)
{
  esp_err_t err = esp_ble_gatt_set_local_mtu(mtu);  //First must set local MTU value.
  if (err == ESP_OK)
  {
    err = esp_ble_gattc_send_mtu_req(m_gattc_if,m_conn_id);  //Once local is set successfully set remote size
    if (err!=ESP_OK)
    {
      log_e("Error setting send MTU request MTU: %d err=%d", mtu,err);
      return false;
    }
  }
  else
  {
    log_e("can't set local mtu value: %d", mtu);
    return false;
  }
  log_v("<< setLocalMTU");

  m_mtu = mtu; //successfully changed

  return true;
}




/**
 * @brief Return a string representation of this client.
 * @return A string representation of this client.
 */
String BLEClient::toString() {
  String res = "peer address: " + m_peerAddress.toString();
  res += "\nServices:\n";
  for (auto &myPair : m_servicesMap) {
    res += myPair.second->toString() + "\n";
    // myPair.second is the value
  }
  return res;
} // toString

#endif /* CONFIG_BLUEDROID_ENABLED */
#endif /* SOC_BLE_SUPPORTED */
